In the 7½ months between now and November's midterm elections, millions of Americans will be whipped into a frenzy over the purported evils in the Democrats' health care bill, egged on by Fox News chatter, Rush Limbaugh's daily sermons, threats of state legislative and judicial action and the solemn pledge of Republicans in Washington to make the fall election a referendum on Obamacare. But in doing so, they may be playing right into the Democrats' hands.

President Obama gave a strong closing argument in the fortnight leading up to the dramatic March 21 floor votes, delivering speeches in the key states of Ohio, Pennsylvania and Virginia and achieving levels of "fired up and ready to go" not seen since his presidential campaign. Such passionate pleas stiffened the spines of his party brethren, who have been anticipating and dreading months of over-the-top rhetoric about the ruinous consequences of a Democrats-only effort to bring the U.S. into the community of nations that make health care available to all their citizens. Indeed, not every Democratic member of Congress has embraced the White House theme that doing the right thing for the nation is more important than preserving individual seats in the Capitol. But enough hearts and minds were changed to allow the Obama-Pelosi tag team to get its majority at long last. (See 10 players in health care reform.)

The falling action in the Senate over the next week or two will only exacerbate the partisan divide in Washington, inevitably mirrored throughout the country for the rest of the year. Republicans in the upper chamber not only will vociferously oppose the Democratic plan to pass the changes to their bill with the simple majority procedure known as reconciliation but will also make it clear that any prospect for meaningful bipartisan cooperation on any and all issues is dead and buried, at least for now.

The President, however, may be indifferent to the acrid fussing of his Republican foes. He will be able to bask once again in the glow of positive press coverage (accented by a momentous signing ceremony), which will focus on four areas helpful to the Democrats' prospects in November: the masterful display of White House patience and competence that got the job done; the elements of the legislation that are in fact consistently popular with large numbers of Americans, such as its insurance-company crackdowns; the return of the meme that Republicans are the party of "No"; and the accompanying rising poll numbers for the Administration and the new law. (See 10 health care reform ads.)

In their comments in the House debate on March 21, Republicans often sounded shrill and angry, sometimes hysterical. This is a real danger for a party that since the 2008 Obama-McCain contest has aimed to appeal to die-hard conservatives at the expense of a broader-based constituency. The illusory belief that a majority can be built from a finite core of animated and agitated souls is what kept Democrats out of the White House for most of the 1970s and '80s, and Republicans are in danger of duplicating that error.

There is no question that the Democrats have handed the opposition party a compelling rationale to fire up its base for the upcoming election. But the bloodiest battle will be fought to define the new health care law for both swing and independent voters (even as disenchanted liberals are still being coaxed back to their stations). (See TIME's video "Uninsured Again.")

Democrats will be joined in the fray by much of the press. For Republicans, this will seem like familiar ground, since generations of conservatives have complained that the so-called mainstream media have been biased against them. Well, get ready, Republicans, for déjà vu all over again. The coverage through November likely will highlight the most extreme attacks on the President and his law and spotlight stories of real Americans whose lives have been improved by access to health care (pushed, no doubt, by Democrats from every competitive congressional district and state). The louder Republicans yell, the more they will be characterized and caricatured as sore losers infuriated by the first major delivery of candidate Obama's promise of "change." The focus on the weekend's alleged racial and gay-bashing verbal attacks by opponents of the Democrats' plan should be a caution to Republican strategists trying to figure out how to manage the media this year.

But fighting back against a supposedly hostile press is old hat for the GOP. A far greater challenge will come from a new quarter. Large segments of the American business community are going to present a formidable ally for Obamacare, either with outspoken support or noticeable silence. From businesses that have been crushed by rising health care costs to pharmaceutical companies cleverly co-opted by the White House early on in the process; from the doctors' organizations (including the American Medical Association) that endorsed the final product to, yes, even the vilified insurance companies  none of these entities are going to join the charge to reverse the new reality of U.S. health care, and many will make it clear that they are resigned to or are actually in favor of the apparently inevitable conclusion.

Add in labor unions, nurses and the AARP, plus the liberal coalition that has quietly worked to support the Democrats' effort, and the political challenge for those who suffered a substantive loss on March 21 becomes clear. The President and his allies will argue mightily in the coming days that the great war over health care has ended. Republicans certainly will make the case that the crusade has just begun. In this semantic skirmish, the White House, bolstered by the momentum of victory and allies old and new, is girded for combat.